Local Anaesthesia

Key facts

• Local anaesthesia blocks pain signals in a defined area of the body while you stay fully conscious.
• It works by stopping nerve fibres in that area from carrying pain signals; the effect starts within minutes and fades once the medicine clears from the tissue.
• Lidocaine is the most widely used agent, applied as a surface gel for skin and mucous membranes or injected for a nerve block.
• Numbness in the treated area is expected and temporary; report anything that lasts well beyond that to the clinician who treated you.

How local anaesthetics work

A local anaesthetic does not sedate the whole body. It temporarily stops nerve fibres in a targeted region from conducting pain signals to the brain. The effect sets in within a few minutes and wears off once the medicine clears from the tissue, usually within one to several hours depending on the agent and the dose used.

Where it is used

Lidocaine covers a broad range of applications: surface numbing gels for skin or mucous membranes, and injected nerve blocks for dental work, minor skin procedures, and small surgical operations. It sits within the wider pain relief group of medicines, though its job here is preventing pain during a procedure rather than relieving pain that is already established. Because it acts locally, it avoids the grogginess, nausea, and recovery time that come with general anaesthesia.

When to check with a clinician

Some numbness and reduced sensation in the treated area is normal and settles on its own. Let the treating clinician know if numbness, tingling, or an unusual sensation persists well beyond the expected duration after a procedure, or if the area becomes increasingly painful, swollen, or warm, which can point to an unrelated complication rather than the anaesthetic itself.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.